The present invention relates in general to high speed communications networks. More particularly, it relates to a fiber optic high speed data network capable of transmitting audio, video, data, low-bandwidth control data, and other similar signals.
There is often a need to transmit information between devices that are physically remote from each other. For example, in some passenger vehicles, non-critical multi-media information, such as video, audio, data, low-bandwidth control data, and other similar signals, must be transmitted between remote devices such as a compact disk player, a control panel, an audio amplifier/processor and loudspeakers. One way of connecting such devices is to provide dedicated point-to-point electrical connections. Dedicated connections, however, can quickly become unmanageable as the number of devices that need to be in communication increases.
For applications that require high speed communications between several remote devices, a communications network can provide a cost effective data transmission medium. The basic function of data communications networks is to make it possible for geographically remote pieces of equipment to communicate with each other simply by connecting with the network. The tasks that must be performed in order to effectively carry out data transmissions in a network are best organized by dividing the required tasks into a sequence of more elementary functions that are organized in some fashion. The precise definition and structure of this aggregate set of functions is called a network architecture. Typically, network architectures follow a linearly hierarchial model in which the functions are organized into a linear succession of so-called "layers". For example, the International Standardization Organization (ISO) has proposed a 7-layered model architecture consisting of a physical layer, a data link layer, a network layer, a transport layer, a session layer, a presentation layer, and an application layer. The physical layer, which is the lowest level of the hierarchy, is concerned primarily with the transparent transmission of a bit stream (regardless of its meaning) across physical communication resources. In local networks, the physical medium may be a twisted pair, a coaxial cable, an optical fiber, or radio.